How do motion detectors work?
James Brown
Laser Pointers shouldn't be in the hands of kids.
JB
Sandra L Sanders wrote:
> I am interested in learning how motion detectors work. One of my co
> workers said that his son shined a laser pointer at a sensor in his house
> and it stoped working, any thoughts on this? Thanks in advance.
Sandra L Sanders
Jacob Ashbury
Passive Infrared (PIR) motions work 'supposedly' from heat and movement. It
seems that heat alone will set one off. I've tried mirrors and they can set
one off- also reflected bright lights can affect some of them it seems.
I am guessing but the laser light probably burnt the "eye" in the motion or
fried part of the board. I'll borrow a laser light and test some of the old
ones I have laying around.
Sun Alarm
Service a priority
North and central Alabama, central Tennessee
ch...@mindsping.com
Sandra L Sanders wrote in message <798hr6$a...@bgtnsc01.worldnet.att.net>...
Joe Paletta
Drive by PIR activation by laser pen carrying thugs!!!
Another hidden false alarm problem !!!!
Joe
PSS
Jacob Ashbury
Imagine- looking through a window (or previously being in a home or store)
and killing the motion without an alarm.
I'll play with this in the shop this weekend.
Joe Paletta wrote in message <799ng2$sej$1...@newsreader.jvnc.net>...
Robert L Bass
>
> Wow, Drive by PIR activation by laser pen carrying thugs!!!
> Another hidden false alarm problem !!!!
Heh, heh. It's right up there with the late Richard "Doc" Cory's problem
with the ubiquitous mylar balloons. Those puppies are apparently so
prevalent that it merited no less than three separate stories in major trade
magazines. Or possibly the FAR comittee simply hadn't come up with anything
else to write about that year. <smile>
Regards,
Robert L Bass
==========================>
Bass Home Electronics
The Online DIY Alarm Store
http://www.BassHome.com
80 Bentwood Road
West Hartford, CT 06107
860-561-9542 voice
860-521-2143 fax
==========================>
Robert L Bass
pointers. The human eye isn't damaged by it because the iris stops down in
the presence of bright light. PIRs have no such mechanism. Yet they
survive brief exposure to sunlight just fine. They can false from exposure
to reflected sunlight though. That's one reason you should never point a
motion detector at a window.
Regards,
Robert L Bass
==========================>
Bass Home Electronics
The Online DIY Alarm Store
http://www.BassHome.com
80 Bentwood Road
West Hartford, CT 06107
860-561-9542 voice
860-521-2143 fax
==========================>
Jacob Ashbury wrote in message <799u15$bdc$1...@camel29.mindspring.com>...
>I wonder if this would "kill" a motion- interesting.
>Imagine- looking through a window (or previously being in a home or store)
>and killing the motion without an alarm.
>I'll play with this in the shop this weekend.
>
>Joe Paletta wrote in message <799ng2$sej$1...@newsreader.jvnc.net>...
>>Wow,
>>
>>Drive by PIR activation by laser pen carrying thugs!!!
>>
>>Another hidden false alarm problem !!!!
>>
>>Joe
>>PSS
>>
>>
>>
>
>
Bob L.
triggering an alarm on a premise. Changed the sensors and had the kids
taken home to their parents in the back of a squad car. One or the oher
solved the problem.
--
Bob L.
The Security Consultant
rob...@digitaldune.net
ICQ# 12280352
IM Name Bob L 3rd
Jeff Montgomery
pointer does not have the power to affect a motion detector how about a laser
sight for a firearm. These lasers are much more powerful and will cause
damage to your eyes.
Jacob Ashbury wrote:
> I wonder if this would "kill" a motion- interesting.
> Imagine- looking through a window (or previously being in a home or store)
> and killing the motion without an alarm.
> I'll play with this in the shop this weekend.
>
ETHolmes
>workers said that his son shined a laser pointer at a sensor in his house
>and it stoped working, any thoughts on this? Thanks in advance.
Assuming that the "motion detector" is a PIR, it responds to a change in the
infra-red level when a body (or something else) passes between it and the
background (wall , floor etc.) that it was "looking" at. The new background (an
intruder) radiates infra-red at a different rate than what it was seeing. If
the change exceeds the PIR specifications in both contrast (the amount of
change-approx 1-2 deg "C") and rate of change (speed), the PIR trips.
I don't believe it stopped working by shinning a laser pointer at it. It may
false it however, depending on the wavelength and intensity of the laser
pointer.
Alarmsrvcs
Assuming that the "motion detector" is a PIR, it responds to a change in the
infra-red level when a body (or something else) passes between it and the
background (wall , floor etc.) that it was "looking" at. The new background (an
intruder) radiates infra-red at a different rate than what it was seeing. If
the change exceeds the PIR specifications in both contrast (the amount of
change-approx 1-2 deg "C") and rate of change (speed), the PIR trips.
I don't believe it stopped working by shinning a laser pointer at it. It may
false it however, depending on the wavelength and intensity of the laser
pointer.
MIKE Responded:
Do you have any idea what you are trying to say in this totally and incomplete
gibberish, UN professional post. < I CONFESS...GOOFY MADE ME DO THIS >
Mike
Alarm Services Inc. (NJ)
28 Years In The Trade
10% Discount To DIy's
One Year Free Monitoring W/Purchase Of A Complete Security System
Visit our web site OR E-mail For Details
http://www.AlarmServicesInc.com
I love GOOFY
Robert L Bass
--
Alarmsrvcs
>From: Robert L Bass <alar...@BassHome.com>
>Date: 2/4/99 8:55 PM Pacific Standard Time
>Message-id: <36BA79F7...@BassHome.com>
Alarmsrvcs
Alarmsrvcs
Alarmsrvcs
Shell
Apparently nothing at all. He just forwarded at least nine of someone
else's posts to news.admin.net-abuse.usenet for no reason that *I* can
figure out.
What's the problem, Mr. Bass?
Are you mad at this guy, or something? Because he doesn't appear to be
spamming, forging, or flooding (or cancelling, for that matter) and thus
is not committing any abuse of the net. And you didn't even include full
headers!
Killfile the little booger and move on. He's being a jerk, but that is
not abuse of the net. In fact, berating others is not even abuse *on*
the net in most cases. You cannot reasonably expect to be protected from
the opinions and the (non-TOSable) behavior of others.
Shell
This post is my opinion and may not coincide with the opinion of anyone
else anywhere at all. No warranty, express or implied...
--
Robert L Bass
Robert
Shell <gur...@notarealdomain.net> wrote in message
news:36BB4AB0...@notarealdomain.net...
Paul Bealing
>workers said that his son shined a laser pointer at a sensor in his house
>and it stoped working, any thoughts on this? Thanks in advance.
How a PIR works:
There may be a policy of not explaining in detail the operation of an
intruder detection device device on this news group. We don't want the
intruders to know too much.
I get the impression from the the lack of information in the other posts
that this may be case.
Would some of you frequent contributors please let me know.
Laser Pointer:
Directing a powerfull or concentrated Infra Red source at a PIR can blind
it.
I have not seen a PIR permanently damaged by doing this.
I haven't experimented with IR from laser pointers, but this is my guess:
A laser pointer puts out a concentrated/directed beam of visible light. The
Infra red content that reaches the target is probably very low, so would not
harm or blind a PIR. The infra red that is emitted is probably not directed
in a fine beam like the light, but rather spreads rapidly like a standard
cheap torch beam.
BTW
I have read that an IR laser is much more dangerous to eyes than a visible
laser of the same power. The natural reaction to a visible bright light is
to blink, minimising the damage. The IR is not visible, so no blink = much
damage.
It is mentioned in another post that direct sunlight can damage PIRs. I have
not found this to be the case. I have many standard indoor PIRs that have
been operating outside in direct sunlight for many years (mostly Crow and
Paradox brands). The only damage I have noticed is to the cases, caused by
UV exposure.
Regards
Paul Bealing
D...@nonegiven.com
wrote:
>Just thought I would ask another question along the same lines....If a laser
>pointer does not have the power to affect a motion detector how about a laser
>sight for a firearm. These lasers are much more powerful and will cause
>damage to your eyes.
Ok guys. Here is the real "poop" on the subject of laser pointers.
Being a gadget loving person, my wife bought me one of these things
for Christmas. It is a class III, 650nm @ 5 mw laser pen. And yes,
it will cause blindness. I have first hand experiance here. Read on.
More than just wanting to have a high-tech toy, I was looking to find
a practical use for this laser. Lo and behold, a few days later I
discovered a fly in our shop on the window. I blasted him (her?) with
the laser for about 20 seconds, and was then able to actually touch it
before it realized something was that close. Was this a fluke? A
week or so ago, I came across another fly, and the same results were
acheived by zapping this one.
So, fellow newsreaders, the word is out. Stock up on seismic
detectors, as the yards of people who own dogs will be invaded by
teens seeking to zap these pests which congregate around the dog doody
on those hot summer days... This is your big opportunity to get in on
the ground floor of this emerging sales explosion. For more details,
send $19.95 to...
Larry
have to deal with blind....oops, sorry.....visually chalanged insects
slamming into us un-announced. And how will the poor things
survive...starving to death because they cant find food....how can you
sleep at night, knowing you have caused hardship for one of God's
creatures. On the other hand, it sounds a lot more fun then blasting them
with a T-18, and less mess too!
Zzzzzzzzzzzzzzzz....ZAP.....AHHHHHHH.......SMASH...z..zzz....z.....ow.:-}
D...@nonegiven.com wrote in article <36bda3bd...@news.cwix.com>...